MSP->IMHO the process should work the same, at every power up. A WSD which 
never 'roams' will experience the simple or trivial case (e.g. in the US always 
receive the addresses of the same WSDBs, and likely pick the same address for 
service every time). But when the device powers up in a roaming state, then the 
situation becomes more interesting.
If you need to configure to have a policy that decides which of multiple 
competing databases you have a relationship with, configure the URI to the 
database.

If your default database has roaming agreements, your configured database can 
refer you to the right one.

If your device can roam, on its own, to places where there is only one database 
(for example, a government run or sponsored database), then we might want a 
discovery mechanism, but I think LoST is it.

MSP->Simplicity? It is not obvious for me how a white space business model will 
support the Authoritative Mapping Server, Forest Guide & Resolver entities in 
RFC5582.
Authoritative Mapping server = Lost Server.  Your DS.
Forest Guide can be part of the LoST server - it's just an entity that 
exchanges coverage information with other FGs to build a referral database.

You can restrict access to the FG to only authorized LoST servers (DS in your 
terms).  That means that if a DS doesn't know what the right DS is, it consults 
the FG, which tells it.  That makes the load on the FG very low.  FGs have no 
root.  It would be perfectly reasonable for a regulator to run an FG as long as 
only DSs in the country could access it.  It would connect to similar FGs 
elsewhere.

It's also possible for anyone who wants to to run an FG with similar 
restrictions - only handling requests from DSs (LoST servers) it knows.

It would be very easy for example, the U.S. WSDB Admins to agree on an FG model 
that worked for the US and connected to other country's DSs.

Brian

If you want to build in some default LoST server URI into the device, as long 
as that server is willing to refer the query to the right LoST server for ever, 
for free, that works.

Brian



On Jul 10, 2012, at 4:00 PM, 
<[email protected]<mailto:[email protected]>> wrote:

Inline:

From: "<ext Rosen>", "[email protected]<mailto:[email protected]>" 
<[email protected]<mailto:[email protected]>>
Date: Tuesday, July 10, 2012 2:50 PM
To: Scott Probasco <[email protected]<mailto:[email protected]>>
Cc: "[email protected]<mailto:[email protected]>" <[email protected]<mailto:[email protected]>>
Subject: Re: [paws] draft document for Discovery

When I do the discovery, I don't know which country I am in.  I can't know 
enough to query the right DS unless we put country boundary polygons in the 
device.

Raj> The WSD could send information (such as GPS co-ordinates, MCC+MNC, SSID 
etc.) to the discovery server which can be used to determine the country that 
it is in. The DS itself is not country specific. It uses the information sent 
by the device to determine which country the device is located in and respond 
with the address(es) of the WSDBs therein.

Of course, I forgot to add to this that if there is the U.S. model of competing 
DBs, then the whole discovery mechanism falls apart, and you need
configuration, because if the device knows who its business relationship is 
with, it can know the URI.

Raj> In such a case it is configured in the device. The device could still 
query the DS and get a list of competing databases and then some policy on the 
device will enable it to choose a preferred DB.

-Raj


Brian


On Jul 10, 2012, at 3:38 PM, 
<[email protected]<mailto:[email protected]>> 
<[email protected]<mailto:[email protected]>> wrote:

Hi Brian,

Comments below: MSP->

Kind Regards,
Scott

From: "ext Rosen, Brian" 
<[email protected]<mailto:[email protected]>>
Date: Mon, 9 Jul 2012 17:27:31 -0400
To: Scott Probasco <[email protected]<mailto:[email protected]>>
Cc: "[email protected]<mailto:[email protected]>" <[email protected]<mailto:[email protected]>>
Subject: Re: [paws] draft document for Discovery

This re-invents LoST without the extensive mechanisms for self organizing 
databases.
LoST has a query that sends location in, with a Service URN (which for this use 
would be "I want a WSDB for this location" and you get back (a list of) URIs.

That's what you propose, without the service URN because you want a special 
location based discovery mechanism just for WSDBs.

What you don't deal with is how a WSDB DS finds out about all other WSDB DSs.  
That's the LoST "Forest Guide".  The FG works without a root, and allows 
cooperating LoST servers to  refer queries to the right server.
MSP->If each WSD vendor arranges a service level agreement with a WSDB DS (or 
provides their own WSDB DS) then it is not obvious to me why a WSDB DS would 
need to find out about other WSDB DSs. Each WSDB DS is independent. If vendor X 
intends their WSD to operate in Country Y, then WSDB DS used by vendor X must 
include appropriate Country Y mapping information (location to WSDB or WSDB 
listing server) in their WSDB DS.

It's not really a great idea to bake a URI into a device.  Who knows what will 
happen over the life of a device?
MSP->Including an address in the device does not imply that the address cannot 
be changed if needed. SW updates, device management or similar can allow for 
changes if needed. I take your point, these changes should be exceptions rather 
than regular events.

The existing LoST discovery mechanism is built for widespread deployment in 
ISPs.   We may need something that works well without that.  There aren't a lot 
of good mechanisms that really work well - you either have a root of some sort, 
or, as you propose, a starting seed.  The root problem is who runs the root, 
and the starting seed problem is the lifetime of the seed.  You note that the 
seed gets nothing out of the exchange - it doesn't get to serve the query, it 
only gets to refer to someone who does.
MSP->It is not clear to me what business model would support a sophisticated 
infrastructure as described in the LoST Architecture & Framework RFC 5582.

I actually think this is not an important problem to solve really well.  The 
most common deployment model is going to be a tower and clients.  The tower can 
be configured, and either the clients learn from the tower, or the tower 
handles the database query itself.  Client discovery in that case could be the 
LoST discovery mechanism.

We have to handle the self organizing case (say a MANET) where one or more 
devices have some other path to the Internet to get to the WSDB.  They will 
need real discovery and may not have a cooperating ISP.  While I really don't 
like configuration, it may be the only viable way to do it.
MSP->Configuration is pragmatic and can be easily deployed

Brian

On Jul 9, 2012, at 5:04 PM, 
<[email protected]<mailto:[email protected]>> wrote:

Hello All,

Please find a link below to a draft submission for the Discovery process as 
described in the Use Cases & Requirements document. We are looking forward to 
your review and comments as well as discussion at IETF#84.

Abstract:
   A white space master device needs to query a white space database and
   obtain information about available spectrum/channels prior to
   operation.  White space databases which contain information about
   available spectrum/channels are associated with a regulatory domain.
   A white space master device needs to discover the relevant white
   space database(s) given its current location and in which regulatory
   domain that it is operating.  The white space database discovery is
   the preliminary step that a white space master device has to perform.


URL:             
http://www.ietf.org/internet-drafts/draft-probasco-paws-discovery-00.txt
Htmlized:        http://tools.ietf.org/html/draft-probasco-paws-discovery-00

Kind Regards,
Scott & Raj



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